I thought you never die because there was never a self to die in the first place. There are the birth process and death process. That which was born is not the same as that which dies. The jellyfish don't undergo the death process but what it was, say 70 years ago isn't the same as what it is now. It is immortal only in the conventional sense just as we are mortal only in the conventional sense.

Read about Henrietta Lacks

Deborah never knew her mother; she was an infant when Henrietta died. She had always wanted to know who her mother was but no one ever talked about Henrietta. So when Deborah found out that this part of her mother was still alive she became desperate to understand what that meant: Did it hurt her mother when scientists injected her cells with viruses and toxins? Had scientists cloned her mother? And could those cells help scientists tell her about her mother, like what her favorite color was and if she liked to dance.

Deborah’s brothers, though, didn’t think much about the cells until they found out there was money involved. HeLa cells were the first human biological materials ever bought and sold, which helped launch a multi-billion-dollar industry. When Deborah’s brothers found out that people were selling vials of their mother’s cells, and that the family didn’t get any of the resulting money, they got very angry.